Dig deeper at SERNEC, a consortium of southeastern herbaria.
Check out EDDMapS.org to see where this has been reported.
Read more about Alligator-weed at Vascular Plants of North Carolina.
Spermatophytes (seed plants): Angiosperms (flowering plants): Eudicots: Core Eudicots: Caryophyllales
Manual of the Southeastern Flora (Small, 1933)
To see larger pictures, click or hover over the thumbnails.
Richard and Teresa Ware rtw_a_philoxeroides
Small, white, rounded cloverlike clusters of tiny flowers are 0.5-0.7" wide, per A Field Guide for the Identification of Invasive Plants in Southern Forests.
COMPARE aquatic plants
James H. Miller, USDA Forest Service, Bugwood.org bug_1539028
Leaves somewhat succulent, obtuse to rounded at the tip, per Weakley's Flora (2012).
Gary Buckingham, USDA Agricultural Research Service, Bugwood.org bug_4723003
Each flower w 5 minute petals (actually sepals) surrounding yellow anthers, per A Field Guide for the Identification of Invasive Plants in Southern Forests.
Julia Scher, Federal Noxious Weeds Disseminules, USDA APHIS ITP, Bugwood.org bug_5376307
Nancy Loewenstein, Auburn University, Bugwood.org bug_5471274
Bracts not keeled. Peduncles 1-7cm, from the leaf axils or terminal, per Weakley's Flora (2012).